Scientists at the Mayo Clinic in Rochester, Minnesota, identified senescent cells in mice that had been genetically engineered to age rapidly using a biomarker, called p16Ink4a, specific to these cells. For the length of the animals' lives, they were injected with a drug that induced only those biomarker-containing senescent cells to commit suicide, while leaving others untouched.

The results were striking: in tissues that contained the labeled cells, including everything from fat to muscle to eyes, selective removal appeared to postpone age-related damage. Treated mice had no cataracts, and showed increased muscle mass, strength, and subcutaneous fat when compared to mice that hadn't received the drug.

This fact is reflected in the proposed apoptoSENS research program, one of the seven branches of the Strategies for Engineered Negligible Senescence. Where the body isn't keeping up with cells that should be destroyed, appropriate forms of biotechnology can could be developed to perform this necessary work - and thereby remove and reverse this contribution to aging. The first array of therapies will probably look much like the targeted cell killing strategies under development in the cancer research community: using bacteria, viruses, nanoparticles, or the patient's own immune system to selectively seek out and destroy cells based on their surface markers.